Plate drier



F. T. POWERS March 3, 1931.

PLATE mman Filed Deo. s, 1928 l NVENT 3R Patented Mar. 3, 17931 PATENT OFFICE FIi-ANKT. TOWERS, or noUGLiis'roN, NEW `Yoiiir PLATE Dimm r Application led December 8, 1,928. Serial No. 324,782.

My invention relates to improvements in apparatus for use in the removal of surplus water from the surface and for the drying out of the plates of metal or glass used in the preparation of photo-engraved printing plates cominonlyused in the photo-nieclianical printing process, known as half-tones and line cuts.

In certain stages of the process of preparation of photo-mechanical printing plates they are subjected to a washing process which consists either of fiowing water over their surfaces or of immersing the plates in the v4water, preferably the former, and thereafter the surface of the plate is dried by any one o-f several processes. These drying processes connnonly consist of applying an absorbent material to the surface of the plate to absorb and remove the water. Vith this process great care must be exercised to avoid injury to the plate and at the same time to completely remove the last drop of water from the surface. The object of this invention is to provide a means of removing the water from plates `without the danger of injury to the plates and to accomplish the removal of the fluid in a minimum of time and ina thorough manner.

I have found that a multiplicity of small jets oficompressed air so arranged and directed that they impinge on the wet surface of the plate is a very effective and rapid method of drying these plates, and I have embodied this invention in an apparatus of the type shown in the accompanying figures. Be it understood that there are many and various forms of apparatus other than that indicated in the figures which will serve as a suitable means of reducing my invention to practice, but the form shown is a preferred embodiment of my invention. Other forms or variations of this form will be obvious to those skilled in the art.

In the accompanying drawing like numbers indicate the same or similar parts.

The apparatus, one form of which is shown by way of example in the drawing, consists of a suitable hollow chamber, 1, preferably of metal, having a series of perforations, la,

in itsunder side. rlrhis chamber is carried on trunnions, 2, arranged to rotate in bearings, carried by the brackets, 3. Through one of these trunnions, which is of a hollow or tubular form, compressed air may be de livered to the chamber by means of a pipe, 3a, from a storage tank,` 4. This tank is kept filled with compressed air at a suitable predetermined pressure by any available means such as an air compressor, 5. Beneath the chamber, 1,.isprovided a table, G, upon the top of` which the plate to be dried is placed. For the more convenient placing of the plate in position on the table the chamber-1, may be lifted by rotating it upon its trunnions, 2, and to fix the position of the chamber, v1, at the proper distance from the plate the said chamber is provided with legs or distance members, 7, by means of which l, the chamber, when lowered over the plate,

will always come to rest at the proper height above the plate.

I have found that for best results it is important that the air nozzles or outlets in the ,j

chamber, l, be spaced between oneaud two inches apart in each direction and that with a given pressure of air in the chamber the height of the under side of the chamber above the plate should be constant.

The method of operation as follows:

The chamber, l, having been lifted to a vertical position by rotating it about the trunnions, 2, the plate to be dried is placed face upward upon the table, 6. The chamber is then lowered to a horizontal position with n the legs, 7, resting 'on the table. The compressed air in tank, 4, which has previously been stored up by the operation of the compresser, 5, is now released by the opening of the valve, 3b, in pipe 3a, and admitting the 9 air to the chamber, l. This high pressure air issuing at high velocity through the nozzles1 la, impinges on the plate and almost instantly removes all surplus water from the surface of the plate. Valve 3b is then closed and compressor 5 then `stores a fresh supply of compressed air in tank 4 in readiness for instant use when the next plate is ready for drying.

Having described my invention and one form of apparatus in Which it may be utilized, I now state what VI claim to be novel and for which I desire to secure Letters Patent:

l. The method vof drying photo mechanical printing plates, which consists of simul taneously impinging air at high velocity upon theentire surface of lone-sident the plate, whereby lthe moisture thereon is substantially instantaneously dislodged and mechanically removed.

2. Themethod of drying photo'mechanicalV i Y printing plates, Which consists of simultanv eously impingiug air at high velocity through a multiplicity of points, simultaneously against thel entire surface of one side of they plate, to mechanically'remove the moisture therefrom.

' 3. In anapparatusi'or-dryingphoto mechanical printirngplates, the combination of a rigid `support* for holding 'the plate in a stationary position, a movable chamber having a multiplicity, of closely spaced apertures positionable in relation to the plate, and

means for suddenlyvsupplying air at high pressure and in large volume to said chamber and through said apertures toydislodge and Vmechanically remove the moisture from-the surface. of the plate. y t. ln an'apparatus for'drying 'photo mechanical' printing plates-,the combination oi rigid supportl for holding th'eplate in a stationary position,.a movable chamber having a multiplicity ofclosely spaced apertures, po-y sitionable in relation to the plate, a storage receiver for air at high pressure, a communicating duct between said chamber and said receiver, and quick operating means forsuddenly opening and closing said duct,l sub stantially as described.-

VSigned at Douglaston, in the county of Queens, city and State of New' York7 this 5 day of Dec. A. D, 1928.

i FRANK T. POWERS. 

